Philosophy of science is about as useful to scientists as ornithology is to birds, said Richard Feynman, Physicist and Nobel Laureate. Like him, the most gloriously achieved people world over often find themselves in the heart of the same concept, treading on the same roads, asking the same questions. American philosopher Daniel C. Dennett's magnum opus – From Bacteria to Bach and Back is as diverse and fascinating as the title itself. It is the culmination of his learning and writing of about half a century. Dennett is a restless philosopher who regales and learns in the company of neuroscientists. This book, he says, is “the tuition” that he pays for all that he learnt from the relentless workers of science.

Not surprisingly, Dennett's work has been hugely praised by philosophers, scientists, and reviewers across the globe. The blurb on the back covers describes this oeuvre of his as “firecracker,” and “enthralling,” to which the words “a rollercoaster ride of a lifetime” can definitely be added.

As psychiatrists and mental health professionals, we often find us asking ourselves difficult questions, some of them, over and over again. These questions range from “Are psychiatric disorders organic or functional in nature?” and “What exactly is consciousness?” to “As human beings, are we on the top of the cognitive ladder?” This book offers many opportunities to look at, reframe, and retry to understand these essential queries. It is a very interesting journey in search of elusive answers to these fundamental questions, and that too, in the company of an astute philosopher and an “amateur neuroscientist:” A rare confluence of expertise of both sides of a coin.

Before we begin, the author warns us to fasten our seat belts as this is not a straightforward simple ride. This is going to challenge all our existing notions and assumptions about everything that we have known till now about evolution and cognition.

The first five chapters of the book, as the author puts it, lay the basis for a profound inquiry into the second part (eight chapters) of the book. The second part of the book takes a closer look at our “existing concepts” of language, mind, and consciousness.

Dennett starts the “journey” with a basic overview of how “evolution” began in the primordial soup that was the earth billions of years ago. From the unicellular eukaryote to the most complex multicellular behemoth, that is the human being, the panorama has to be read to be experienced. In this evolutionary odyssey enters Rene Descartes, the French philosopher, mathematician and scientist, whose ideas still hold sway over the populace. “Cartesian Gravity” is the wonderful name Dennett gives to the enduring charisma of the great man.

”Competence without comprehension” or the bottom-up approach to evolution is the recurrent and underlying theme of this work. The author strongly and vehemently refutes the idea of an “Intelligent Design” or a “purpose” to evolution. He, rather, reiterates the fact that nature picks on a “single mutation” in a “lazy”, “purposeless” fashion and the “design” enhances itself over the eons.

Dennett proposes 4 types of living organisms on the evolutionary ladder – “Darwinian, Skinnerian, Popperian, Gregorian.” Humans are “Gregorian.” The capacity to learn increases along the scale from “Darwinian” to “Gregorian.” The competence also progresses in the same fashion. Information, “semantic information,” is what is needed for functioning. Dennett utilizes a substantial part of the narrative to discuss semantic information in all its glory. The fact that semantic information enhances competence is strongly underscored. According to Dennett, useful semantic information is “freely available” to successfully evolved organisms, “plagiarism is the norm”, which is quite contrary to the existing human notions of intellectual property rights!

”The Darwinian field” is a three axes graph which Dennett introduces to explain evolution of complex concepts such as culture. We get introduced to “memes,” cultural memes implicated in the rapid progress of evolution in a very short span of time. “Words” or language, says Dennett, are like viruses, they spread and infect. Culture, memes, and words are the tools for thinking which have made us Gregorian.

Dennett also talks about the building blocks of the nervous system, the neurons. He calls them “the mules”, “survival”. Neurons do their work pretty well, without being aware of what they are doing. They are “competent” without “comprehending.”

So, then, what is “Consciousness?” An illusion that arises when subsets of neurons competently go about doing their job, much like “the folders on a desktop.”

Where is Bach in all of this? Dennett describes Bach, his musical roots, his career in music, and his legacy, to describe his “competency” concept.

And what about the soul? This is the question any self-respecting philosopher would always like an answer to. “Yes, we have a soul, but it's made of lots of tiny robots!” screams the headline for an interview with Dennett by Giulio Giorello in Corrieredella Serra, Milan, 1997. No better way of putting it.

Modern neuroscience has given us a lot to think about. Not only in terms of the hi-tech approach to basic cognitive processes, but also the amazing and startling findings that we are forced to confront in our quest for a better understanding of who we are and our consciousness. Yet, a lot more is needed to completely understand the concept of consciousness. This book provides the basic tools necessary to continue the inquiry into the limitless universe of consciousness.

The language of the book can be dense at times, necessitating a back and forth. However, the fabulous new terms coined by Dennett, time and again, and scattered throughout the book, more than make up for the aforementioned denseness, and give a fresh twist and meaning to the concepts that many readers may not be well versed with. The size of the book can appear forbidding – after all it aims to capture a snapshot of our internal universe! The footnotes and references also make interesting reading – a testimony to the quality of homework that has gone into making an once-in-a-lifetime kind of book.

Are we going to read this tome again? Yes, no doubt about that. We're sure that we will find something new with each read. It is not often that a highly rated philosopher can understand neuroscience well and share his knowledge with those who are neither.

Dennett has successfully aroused an appetite for more searching, with his book serving as an irresistible hors d'oeuvre. There's all this and so much more in the book and we're not going to give it all away! In one line, the book attempts to comprehend the origin of human consciousness and an attempt like this in itself is formidable. Our verdict – thought provoking, incredibly conceptualized, and refreshingly different. Indisputably the book is a must read.